Development of indicators for cephamycin bioassay.

Several species of bacteria have been tested, for their sensitivity to cephamycin C and other beta-lactam antibiotics with a view to develop an indicator system for identification and quantitation of cephamycin. During the study, a mutant derived from E. coli K 802, exhibited a 10-fold increased sensitivity to cephamycin C than E. coli ESS (reference strain)1,2 and was designated as supersensitive E. coli K 8025. Another interesting feature observed during the investigation was that a strain of Serratia, showed a high degree of resistance to penicillins and cephalosporins however, it was sensitive to cephamycin and its derivative. It has been suggested that E. coli K 8025 and Serratia would serve as good indicator organisms for detection and quantitation of cephamycin.